Wind turbines are used to generate energy by harnessing power generated by wind flow. Wind turbines generally work by converting kinetic energy from the wind into mechanical energy. The wind turns a rotor that is connected to a generator, which in turn generates electricity.
Wind turbines are inherently inefficient at low wind speeds and when the wind changes direction.
At low wind speeds, the torque created by the wind against the rotor may not be large enough to overcome the turbine's initial resistance to rotation. However, that same wind speed may be powerful enough to maintain the rotational speed of a turbine already in motion. As a result, the turbine may never even get started at wind speeds that would be adequate to produce energy. Typical wind turbines lose out on the energy that would be generated if they were able to overcome their initial resistance to rotation.
Accordingly, a need exists for a wind turbine with improved efficiency, particularly a wind turbine that operates at wind speeds below the speed needed to induce breakaway torque and above the threshold required to power the rotor once the initial resistance is overcome.
In addition, typical wind turbines have exposed rotors. When wind changes directions, the wind against the previously leeward side slows the rotor slows the rotation. In addition, even without changing wind directions, the wind force against the leeward side reduces efficiency.
Therefore, a need exists to provide a wind turbine that shields the rotor from aerodynamic inefficiencies created by the incident wind pressure against the leeward side of the rotor.
Further, exposed rotors can be a physical hazard. As a result, there is a need for improving the safety of wind turbines, particularly by reducing the danger imposed by the rotor mechanism.